Server-Side State for Charts

[joepavitt]

Description

#61 captured the need for server-side state management for all of our widgets. We do this by storing the latest msg.payload against each widget, however, for charts this doesn't encapsulate the full picture as we actually need to store a history of msg.payloads, or often a merger of payloads (e.g. if an array is provided with multiple data points), so we need to deep dive into charts specifically and identify, architecturally, how this can be achieved.

Epic/Story

#61

Have you provided an initial effort estimate for this issue?

I have provided an initial effort estimate